This invention relates to the inhibition of cell growth.
Cell-cell interactions play a central role in initiation of many immune responses. Lymphocyte recognition of surface components on adjacent cells leads, in some cases, to proliferation and/or differentiation of the lymphocyte. Plasma membranes isolated from cells, or artificial membranes (liposomes), which bear the relevant isolated membrane factors, can trigger responses that are normally initiated by cell-cell contact (Mescher et al. 1982 Adv. Exp. Biol. Med. 146:41). Evidence supporting the importance of cell contact in regulatory events includes the finding that isolated plasma membranes inhibit the growth of 3T3 cells in vitro (Whittenberger and Glaser, 1977, Proc. Natl. Acad. Sci. 74:2251), and that such inhibition appeared to be cell specific (Peterson and Lerch, 1983, J. Cell Biol. 97:276); and probably caused by a membrane protein (Wittenberger et al. 1978 Proc. Natl. Acad. Sci. 75:5457).